[Sync] Fixing sync_driver lint violations and adding PRESUBMIT lint check.

components/sync_driver/fake_generic_change_processor.h

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef COMPONENTS_SYNC_DRIVER_FAKE_GENERIC_CHANGE_PROCESSOR_H_
 #define COMPONENTS_SYNC_DRIVER_FAKE_GENERIC_CHANGE_PROCESSOR_H_
 
+#include <string>
+
 #include "components/sync_driver/generic_change_processor.h"
-
 #include "components/sync_driver/generic_change_processor_factory.h"
 #include "components/sync_driver/sync_api_component_factory.h"
 #include "sync/api/sync_error.h"
 #include "sync/internal_api/public/base/model_type.h"
 
 namespace sync_driver {
 
 // A fake GenericChangeProcessor that can return arbitrary values.
 class FakeGenericChangeProcessor : public GenericChangeProcessor {
  public:
@@ skipping 36 matching lines @@
       SyncClient* sync_client) override;
 
  private:
   scoped_ptr<FakeGenericChangeProcessor> processor_;
   DISALLOW_COPY_AND_ASSIGN(FakeGenericChangeProcessorFactory);
 };
 
 }  // namespace sync_driver
 
 #endif  // COMPONENTS_SYNC_DRIVER_FAKE_GENERIC_CHANGE_PROCESSOR_H_